All those receives/sends were just for an example. In real life, there would be constant switching from mixer mode to user mode for creating new tracks, deleting tracks, adding fxs from templates, undo/redo, region creating/browsing and so on. All kinds of info should be stored in reaper.
Mixer mode should store arm states, pan, volume, solo, mute by itself, so that any of those states could be displayed on the LCD.
Let's leave it for the moment. For now, I have issues with the main function - successfully sending sysex data to the controller. I need @Justin to tell me if I'm doing something wrong or maybe it's oscii-bot's fault and not mine.

Those slots in your example aren't constant, so I probably won't use that method to store data. I prefer having a string with understandable name, like reaperTrackNames, that contains names of all tracks.

Could you, please, provide me with an example of how to make this string:
"oh|hello|world" into this "oh|goodbye|world"?